Rolling mill conveyor control systems



Aug. 25, 1959 B. E. FRANKENFIELD ETAL ROLLING MILL CONVEYOR CONTROL SYSTEMS 5 Sheets-Sheet 1 Filed Feb. 25, 1954 INVENTORS. B. E. FRANKENF/ELD TTTTTT AND A; MILLER BY 1A.

Aug. 25, 1959 B. E. FRANKENFIELD ETAL 2,

ROLLING MILL CONVEYOR CONTROL SYSTEMS Filed Feb. 25, 1954 5 Sheets-Sheet s PHOTO E L EC 7916 RELAY 49972327 I RELAY i gfiglfimsflf sazcrox? so; ENG/D T 252 5 l V EFT s54 EFTOR 63 I E LSOLENOID I N V EN TORS 5.5. FRANKENF/ELD AND A..M/LLE/? Aug. 25, 1959 B. E. FRANKENFIELD ETAL ROLLING MILL CONVEYOR CONTROL SYSTEMS Filed Feb. 25, 1954 5 Sheets-Sheet. 4

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F ja Q2 279 T -fi H DISPATCH J00 g am's: O 101 Pl/ HER k. INVENTORS/ 2 4 8.5. FRA/V/rENF/ELD /j AND A.E.M/LLER United States Patent ,90 5 phm eu tCONY YQBQQ IRhh Yh EMS Bruee 'lh Frankenfield, Chicago, an Anna Miller, 9 h. it side -t: s -shots, o We te n. E ec ri Company, Incorporated, New York, N. Y., acorporatl twr trj Application February 25, 1954, Serial No. 412,424

s out n (Cl sh-4h) ialflYell at tQ rolling m ll l qh eyq systems. llii fii i l t 1 I l? F lt ti n, 19W,IQ1l lg..P ?1 S.PI9 i l with. ll sqe m ushin ml h n i te me ate min a nand inore particularly tofbill et-di spatching systems for ishing mill, a conveyor for advancing billets from the furnace to the mill and a pusher for pushing billets from the furnace onto the conveyor, the billets are sometimes ela-trend betwe atht te med a e m and t t nish n mill in such amannei that alternate billets ,go1 through;

01,1? m eriiesi fl a e f t e n shi hill hd t e. he i. o fihfq i t n the i s reases n h n.- ishl l n n e P st; t e sbq nh appara us or l'i aati e ly Pt ll l1 1 l tht qu h hamil spaced that alternate billets are spaced a minimum safe stance part and ub a ia l o f tht r partt li t of theinvtht ch t r v d ew nd 3 prove d rolling mill conveyor systems.

l9 llj rnpbi 1 h? i tenti n JQ ,p v de w et ts zi htp t e nve iqh o Provid a b l i elqm il tsm e billets metedutoma i a bij e q f i the fed. t e mil i mea u j n the as n ll! i lness? d spatch, 1 QI1Y YOL II,

e ef en ha thhsat t e deli ery, c nveyor nidf? a llt z w t i 5l l1 qmflmiumaw t thev isi t l w lt aw ab ll s, ehdyahqs d. u ema tlly i ollghlt i itbl lli g, r ill a d; i erhled htemi t; le es mall rs s y. t e esp P se P fi fi lishing mill. A photoelectricdetecting device stopseach f 'b ld r pe e tt et thr. tua ed. N ip t a ly l i t i l erepatt" and. q i ahe i he; t rmediate mill actuates thedispatch conyeyqr to feed a billet from the delivery end thereof to the delivery conveyor when the preceding billetis at a predetermined;

ptiiiit inf the intermediate mill,,and also actuates the pusher to feed another billet to the dispatch convey or,

whichfm'oves the latter billet to the temperaturemeasuring device and stops it there. Measuring means t i l sims m iets m l, m su ese chb l et, an

delays the dispatch of the second succeeding billetinlac cord ance with the length .of the billet being measured.

2,900,852 Patented Aug 25 ice Themeasuring means is so constructed and arranged that the dispatch of each billet to the roughing mill is not delayed by the length of any non-alternate preceding;

billet;

A complete understanding of the invention maybe obtained from thefollowing detailed description of a rolling mill conveyor system forming a specific embodi-j' ment thereof, when read in conjunction with the appended drawings, in which Fig. 1 vis a schematic, top plan view of an apparatus forming one embodiment of the invention;

Fig. 2-is a viewof a portion of a control circuit of the apparatus shown in Fig. 1;

Fig. 3 ,is a view of another portion of the control circnit, the top thereof fitting to the bottom of Fig. 2;

"Fig. 4 is a View of the remaining portion dfthe control circuit, the top thereof fititng to the bottom of Fig. 3; and

Fig. 5 isa schematic View of the apparatus. Referring now in detail to the drawings, there is shown in Fig. 1 an apparaus for dispatching billets 11 to a mill,

dividing alternate billets in two paths and spacing the billets ineach path a minimum distance apart regardless of variations in the lengths of the billets. This apparatus includes a'pusher 10 of a well-known type for pushing" billets 11 of copper into and througha furnace 12, which heats the billets, to a suitable temperature for rolling.

When'the pusher is actuated, it pushes one billetinto the furnace andpushes a heated billet out of the furnace" onto a dispatch conveyor 15,whichmoves the heatedbillet endwise toward a continuously running delivery conveyor 16. "As'the billet nears the end of thedispatch conveyor 15,1it breaks a beam of light from a projector 17 to a photoelectric cell 18 of a well-known type, which is responsive to blue light only, which, of course'fis' present in'white light but notin red light from a heated billet, and the cell 18 causes the conveyor 15 to coast to a stop as the billet reaches a position clearing the beam" of light at the endof the conveyor 15.

YThe' billet later is fed from the dispatch conveyor 15 to the delivery conveyor 16, and the conveyor 16 feeds the billet through a first pass 32 Ma roughing mill 33 The billet drops" from the first pass to a guideway 34, aildthe lighttherefrom impinges on a photoelectric cell 35 to actuate a pusher36 to feed the billet'through a second pass '37, which rollsthe reduced billet and feeds it around'a reversing guide 38 to a third pass 39. The third pass '39adva'nc'es the billet therethrough onto a tilting shelf 40, and th e billet' actuates faphotoelectric cell 41 to tip"theshelf" to drop the billet onto a conveyor 42,, which feeds the elongated billet back through a fourth, pass 43 ofan intermediate mill 46 to a guide44. If the 1: billet actuatingthecelll ll is somewhat greaterthan min-Q imuni length, it actuates a photoelectric cell 56 simultaneously with'the cell 41, and if thebillet is near a'maximnm length, itlactuates'a photoelectric cell 57 simultaneously L with its'actuationof the @1141. Thus, thecells 41', 56,1 and 57 measure the 'billets as short, intermediate and long, and delay the dispatch of secondly succeeding billets measurement, as will bebrought in accordance with that out hereinbel'ow.

The guide 44 reverses the billet back to a fifth pass 45,

which advances and reduces th ebillet to rod form and feeds it alonga guide 47 to a pivotal selector guide 481, The guide 48 may be held by a pneumatic piston 49, either I in aposition guiding the reduced billet to a pass 50 or a pass 5'1df afinishingmill 52'. The passes 50 and Sliced f to passes 53 and 54) respectively, which advance the fur-1" ther reduced frods to subsequent passes '55, the increased length of the billets requiring two passes to keep up with the roughing mill 33andthe intermediate mill 46 As the billet moves from the fifth pass along the guide T47, light. therefrom actuates a photoelectric cell 60, I

which, after a predetermined delay proportional to the length of the preceding billet, starts the pusher and the dispatch conveyor 15. The conveyor then feeds another'billet to the continuously running delivery conveyor 16, and the pusher 10 pushes another heated billet out of the furnace 12 onto the conveyor 15, which feeds it to the light-responsive tube 18 which stops the billet at the end of the conveyor 15.

To automatically feed the billets 11 (Fig. 1) through the furnace 12 to and through the rolling mill, switches 79, 80 and 81 (Figs. 2 and 4) are closed. The switch 80 supplies power to conductors 82 and 83 from a powerline. The projector 17 is energized to actuate, through the photoelectric cell 18, a photoelectric relay 90 of a wellknown type to keep open contacts 91, which are open when there is no power on the relay 90 and also when the cell 18 receives white light, but are closed when the beam from the projector 17 is cut off from the cell 18. The switch 79 is set closed and a momentary switch 94 is held closed to actuate relays 95 and 96 to close contacts 97 and 98 in a powerline 99 to energize a motor 100 driving the dispatch conveyor '15 and a motor 101 actuating the pusher 10 (Fig. l). The pusher 10 pushes the first heated billet from the furnace 12 onto the dispatch conveyor 15, and the switch 94 (Fig. 4) is held closed manually as the first billet travels past the photoelectric cell 18 to the delivery conveyor 16 (Fig. 1), which is running continuously and feeds the billet to the first pass.

The pusher 10 and the dispatch conveyor 15 then advance a second billet, and as it passes the cell 18, the cell 18 is darkened to actuate the relay 90 to close the contacts 91 while the billet is going past the cell 18, and the switch 94 is released to stop the billet at the end of the conveyor 15. Momentary closing of the contacts 91 actuate a relay 110 (Fig. 4), which locks itself in through holding contacts 111 and contacts 112 of a conveyor actuating relay 113 and closes contacts 135. When the switch 80 was closed, a relay 116 pulled up through contacts 117, locks itself in through holding contacts 118 and closes contacts 119 so that, when the starting switch 81 was closed momentarily, a relay 128 was actuated. The relay 120 closed holding contacts 121 and contacts 122 and 123 to lock itself in and actuate a relay 124 and a time delay relay 125. The relay 124 opens contacts 126 and closes contacts 127, 128 and 129. Closing of the contacts 135 by the relay 110 actuated a relay 136 to close contacts 137 and open contacts 138 and 288. The opening of contacts 288 deenergizes the relay 120 to open the contacts 121, 122 and 123. By this time, the time delay relay 125 has been timed out to open contacts 141 to drop out the relay 124 to open the contacts 128 and 129 so that closing of the contacts 137 merely sets up the circuit to the relay 113, which includes holding contacts 142 and contacts 143 for actuating the motors 100 and 101.

When the first billet, which is advanced through the roughing and intermediate mills at a predetermined rate of speed, is advanced through the third pass 39 (Fig. 1), light therefrom impinges on the cell 41 as the entire length of the billet goes therepast. The cell 41 actuates a conventional photoelectric relay 144 (Fig. 2) to close contacts 145 concurrently with the illumination of the cell 41 so that a relay 146 is actuated concurrently with this illumination. The relay 146 immediately closes contacts 153, 154, 155, and 156, and opens contacts 158. The contacts 156 actuate a relay 161 to close contacts 162, 163 and 164 and open contacts 165 to drop out a return solenoid 166 actuating a cylinder (not shown) to hold up the shelf. The closing of the contacts 164 actuates a tilting solenoid 171 to tilt the shelf to drop the billet being rolled when the tail end of the billet clears the cell 41 to drop out the relay 146 and reclose the contacts 158. As the shelf tilts to discharge the billet it opens a limit switch 286 to deenergize the relay 161,

whereupon contacts 164 open and contacts 165 close. The opening of contacts 164 deenergizes the tilting solenoid 171, and the closing of contacts 165 energize the return solenoid 166 to return the shelf to normal position.

If the billet is short in length so that it is not as long as the distance between the cells 41 and 56, the relay 144 is deenergized before a relay 181, actuatable by the cell 56 (Fig. 3), is actuated so that the contacts 154 of the relay 146 are not closed simultaneously with contacts 182 of the relay 181 so that a relay 183 is not energized. However, if the billet is longer than the short length fixed by the distance between the cells 41 and 56, the cell 41 maintains the relays 144 and 1 46 closed while the cell 56 actuates the relay 181 to close the contacts 182, and this actuates the relay 183 to close contacts 184 and 185, the contacts 184 being holding contacts for the relay 183. The contacts 185 set up a circuit to a timer 187, and, when the billet now at the third pass later goes through the fifth pass 45, it actuates the photoelectric cell 60 to actuate a photoelectric relay 192 to actuate a relay 191 by closing contacts 193. The relay 191, while actuated, closes contacts 194, 195, 196 and 197. Closing of the contacts 1% starts a timer 199, which, after a delay of a minimum period of time desired for the dispatching to the roughing mill of the billet next succeeding the billet at the fifth pass, closes contacts 198 to actuate the relay 120 to close the contacts 122 to actuate the relay 124 which actuates the relay 113 to start the dispatch conveyor motor 100 and the pusher motor 101, and this billet will be just a minimum safe distance behind the billet preceding it through the mill, the billet at the fifth pass, the timer 199 being set for such conditions.

However, assuming the billet at the fifth pass to be of a medium length and to have actuated the cells 41 and' 56 simultaneously, thereby actuating the relay 183 and setting up the timer 187. Then, when the billet goes to the fifth pass and actuates the relay 192, the timer 187 immediately is started and opens contacts 201 and holds the contacts 201 open until it times out. When the billet reaches the fifth pass and actuates the relay 191 to close the contacts 196, the timer 199 is started through a circuit including contacts 202 of a timer 203, contacts 204 of a time delay relay 205 and contacts 206 of a relay 207, which is energized on alternate billets and is deenergized on the other billets by a ratchet relay 211.

The ratchet relay, upon energization, closes contacts 9 212, leaves the contacts 212 closed as it is deenergized,

then on the next energization opens the contacts and leaves the contacts open on deenergization. Then, as the actuated neither the cell 56 nor the cell 57 simultaneously with the actuation of the cell 41, the relay 207, being closed by the contacts 212, opens contacts 206, 214 and 215 and closes contacts 216, 217 and 218 so that as this next succeeding billet moves to the fifth pass and actuates the relays 192 and 191 to close the contacts 196, the timer 199 is not energized due to the contacts 201 being held open by the timer 187. Then, as the timer 187 times out, the contacts 201 reclose to actuate the timer 199 through the contacts 196, contacts 221 of a timer 222 and the contacts 218, and the billet resting on the delivery end of the conveyor 15 is automatically conveyed to the conveyor 16, which starts it through the mill.

Whenever the timer 199 is actuated to dispatch a billet through the mill, it also opens contacts 231 to break holding circuits to relays 183 and 232, the relay 232 being actuated through contacts 233 of a relay 235 and having holding contacts 234. This drops out the relays 183 and 232 to open contacts and 239. The opening of contacts 185 and 239 deenergizes the timers 187, 203, 205 and 222 to reset them for timing the next billet to pass through the mill. Whenever a billet is going through the thirdpass, it illuminatesthe photoelectriocell 41 to actuatej the relays 144,- 146, 161. andw21-1, Theratchet relay 1.211 is) actuatedby each billet coming through the thirdtpass and holdstheicontacts 212 closedaon actuation by. everyasecond billet. until :the. next {succeeding billet comes through the third pass; and keeps the contacts 212 open; onactuation by. other billets .so that the;relay 207 is. held energized on. actuation by every-second billet and is: held deenergized'yon actuation by. the other billets. When :the relay 2.07 is held energized,vit sets up circuits tothe timedelay relays 203 and 205,for energization by billets long enough to: at least simultaneously actuateythe cells 41 and 56, and prevents startingof the timers 187 and ZZZrat-this time. On deenergizationof the relay 207;.ritlsets up circuits to the timers 187 and 222for energization by. billets long .enoughto actuate at least the .cell. 56: concurrently with, the.;.cell 41,:and breaks the energizingcircuits tothe timers: 203 and 205'. Thus, the timers 187 and 222are subject to .actuation by the billets alternate to .one another goingthrough the third pass, and ithe timers 203 and-205 are subject. toactuation by the. other billets spaced betweenthese alternate billets, provided, of course, the actuating billets for the relays 203 andu205 are sufi'lciently long to actuate them.

;Whenever the relay 207 is. deenergized as a billet goes through the third: pass, the relays. 183. and the contact 184 'are locked in ifithe .billetris of medium. length .or long, respectively. If the relay; 207 is energized so that the contacts 218 to .the timer 199. are closedassthat billet subsequently goesthrough the fifth pass and calls the timer 199 for the dispatch of another billet from the conveyor 15, this.call is effected through the contacts 206 .of therelay 207. .Thus, the relays 187 and 222 have snoz'efiect on .thedispatch of the next succeeding billet. to: the one to, Which the relays 187. and .222 have just been actuable by. Similarly on. the next billet going through the third pass 39,: the relay 207 is energized so that-the timers 203and 205 are subject to actuation by this billet, and when this billet goes through the fifth pass 45, the contacts 218 are closed so that, if one of the timers 187 and 222 had been energized, that timer controls the actuation .of the timer 199 for the dispatch of the next billet from the conveyor 15. Thus, each billet dispatched .by the immediately preceding billet is dispatched as. close as possible to the secondly preceding billetwithout regard'to the length of billets alternate with the.:billet to be dispatched. The timers 187 and 222 are controlled only by the billets going through the same finishing passes as the billet to be dispatched, and the-,timers203 and 205 are controlled only by the billets goingthrough the other finishing passes. A ratchet relay 261 is actuated on each actuation of the relay 191 by-abillet going through the fifth pass 45, andialternately-keeps contacts."262 open and closed and contacts 263 closed and open. Thus, a solenoid 264- for actuating a valve. tothrow the guide 48 to the right is actuated. alternately .with: a solenoid 265 operable to actuate thexvalvezto. throw the guide .48 to the left. 1 Aimanuallyoperable switch 271 is provided for actuating a..relay272 .to close contacts. 273, 274 and open contacts 275 and 276 to hold the shelf 40 tilted. A relay 281 is 'operable by a momentary switch 282 to hold contacts 283 and 284 open and contacts 285 closedto actuateathereturnsolenoid 166 to prevent tipping of. the shelf 40 while the switch 282 is actuated. The relay 136 isaproyided with contacts 288 for resetting the relay 120 whenever the relay 113. is actuated to start the conveyor motor100 rand pusher motor 101. By dropping out the relay..120, the circuit to the relay 124 is broken to drop .out thislatter relay, which cancels the call for the billet that is being dispatched by dropping out the relay 116.

anuoperator closes-the switchrfil .momentarilyto actuate sequentially the relays 12.0, .124, 113 :and .95 and. 96. to start thepusher motor 101 and the dispatch conveyor motor 100. The pusher .10. pushes a billet onto the dispatch conveyor 15, which advances it to the. end thereof, and as the .billet momentarily breaks the beam of light from the projector 17 to the cell 18, it actuatesthe photoelectric relay. to; actuatetherelay which locks, in through contacts- 111.and actuates the relayw136v The relay 136 then closes the .contacts 137 and opens contacts1138. Actuation of the. relay 136 opens the contacts. 288 to drop out therelay 120, and opening of the contacts-.138 occurs .before the closing .ofthe. contacts 137 todropout the relay 113 to stop the motors 100 and 101, and the. billet comes to a rest at the end of the dispatch conveyor 15. r r r .1Theoperator then closesthe switch 81 momentarily again 1to-.-actuate.therelays 120, 124 and 1 13through the contacts 137 .to again start the motors .101 and 100, which feed the billet oil the end of .the dispatch conveyor to the delivery conveyor 16 and bring another billet'from the furnace to theend of the dispatch conveyor, at which time the secondrbillet darkenscthe photoelectriccell .18 to stop the motors 100 and 101 by dropping out'the relaysy136 and:1:13. ,The relay is .dropped outby momentary energization of. the relays 136 to break the circuittothe relay 1;24-.which also drops out.

.-. As =thepfirst billet goes through the thirdpass, it .actuates the photoelectriccell. 41v to actuate the relays 144 and 146 simultaneously therewith. If the billet. is. shorter than medium lengthitd0esn0t actuate either of the .cells 56 and 57 simultaneously. withthe. actuation ofthe cell 41 so that none of the circuits to the timers 187, 203, 205 and 222 is set. up. That isyneither the relay232 nor the relay-183is actuated and locked in by the shorterbillet going through the third pass. If the first billet going through the third pass. is of medium length sothat it actuates the cells,41.'.and 56, simultaneously, the relays 146-.and,.181 are actuated simultaneously and actuate the relay 183 which locks itself in and closes the contacts 185 in the actuating circuits of the timers 187 and205. If-the billet is longer than medium length, it actuates the cells 41 and 57 simultaneously to simultaneously actuate the relays 146 and 235 thereby closing contacts 153 and 233 simultaneously to momentarily energize the relay 232 which locks itself in throu'gh holding contacts 234. A .After the first billett'ravels fromth'e third pass =to-the fifth'ipass, it goesthrough the fifth pass to actuate the cell 60 to actuate the relays 192 and 191 successivelyto close the contacts 194, 195 and 196, and since-none of the timers 187, 203, 205 and 222 have been actuated prior to the first billet, the" contacts 201, 221, 202--arid 204 are all'closedso that the timer 199 is-act1iated- 'iin mediately. Then after apredetermined, minimum delay, the timer-199 opens the contacts 117 and closes coir tacts-198 to the relay 120. r This predeterminedrelay isbrought about by the fact that the timer 199 is a well known type which must beenergized for a predetermined lengthof tirnebefore it actuates any contacts. Whjen' theft-111161199 is denergized or is timing, the contacts 117 and 198 atom the positions shown in Fig. '4. Whenthe timerl99etimes out (ends its timing cycle) it opens. eontacts;-117 andcloses contacts 198. This closes holding contacts 121 and also closes contacts 122 to actuate'the relay 124 which locks itself inthereby closing-the eontacts 128 andj129. Assuming the second billet to have arriyed atthev dispatch end of the dispatch conveyor-15 so that the relay; 136 is energized, the relay 113 is ener gized whenrthe contacts. 128 are closed by the relay 124, and the motors 100.and .101 are started to send the second billet to. the mill and .bring a third billet to the delivery end 10f theudispatch conveyor '15.; r

As the first billet goes through the fifth pass and actuates the. relays 192 and 191 so that the contacts 194 and 195 are closed, if the first billet was of medium length and had actuated the cells 41 and'56 simultane- 'ously going. through the third pass,"the relay 183 having locked in through contacts 184*and 231, closing of the contacts 194 actuates either the timer 187 or the timer 205 depending on whether the relay 207 is man energized condition or deenergized condition. Since the relay 183 remains locked in, the contacts 185 remain closed, even though the billet has cleared the cell 56 and the contacts 182 are now open. Assuming that the relay 207 isin a deenergized condition, the timer 187 is started by the closing of the contacts 194, and, as it is energized, it opens the contacts 201 until it times out. It will be seen, of course, that the timer 187 opening its contacts 201 has no effect on the dispatch of the second billet inasmuch as the relay 207 is deenergized to hold contacts 218 open and contacts 206 closed. If the relay 232had been locked in by the first billet being long to actuate the cells 41 and 57 simultaneously, the closure of the contacts 195 actuates the timer 222, which interposes a longer delay to the actuation of the timer 199 by the second billet than would the'tim'er 187 so that the third billet would be spaced a sufficient minimum distance from the first billet. v

As the second billet goes through the third pass and actuates the photoelectric cell 41,.the photoelectric relay 144 is actuated to actuate the relays 146, 161 and 211 sequentially. The relay 211 changes the condition of the contacts 212 from opento closed until the cell 41 is again actuated. Closing of the contacts 212 actuates the relay 207 to open contacts 214 and 215 to the timers 187 and 222, and also opens contacts 206 in the actuating circuit of the timer 199. The relay 207 also closes the contacts 216 and 217 to set up the circuits to the timers 205 and 203, respectively, for actuation by the second billet if that billet is greater than a short length billet. The relay 207 also closes the contacts 218 in the energizing circuit of the timer 199 in series with the contacts 201 and 221 of the timers 187 and 222. Consequently, assuming that the first billet has actuated one of the timers 187 and 222 when the second billet goe'sthrough the fifth pass to cause the contacts 196 to be closed, the timer 199 is not actuated until thecontacts201 close in the case of a medium length billet or'until both the contacts 201 and 221 close in the case ofa long billet.

The first billet having cleared the cell 60 as the second billet goes through the third pass, the second billet sets up the timers 205 and 203 if it is of long length, or the timer 205 only if of medium length. Then, when the second billet'actuates the cell 60, the timers 205 and 203 are started, and immediately open contacts 204 and 202 until they time out, which occurs at a time sufficiently after the second billet has left the fifth pass that the fourth billet Will not be dispatched until, just aminimum safe distance is presentbetween the second and fourth billets- Thus, itwill be seen that the timers 187 and. 222 are .actuatabie for every second, or even-numbered, billet, and the timers 205 and 203 are operable alternately with the timers 137 and 222' for the other, or odd-numbered, billets, and each of these timers operates independently of the previous operation of the timers operable alternately therewith so that the lengths of billets odd in the order of disptch do not interfere with those even in the order of dispatch or vice versa. 1

The above-described apparatus dispatches each alternate set of billets (the odd-numbered billets) one after another as closely together as is possible Without jamming one set of finishing passes of the finishing mill, and also dispatches the other setiof billets (the evenmumbered billets) in .thesanie manner with respect to" the other series of finishing passes inthe mill. J As'a conse'quence,

both series of finishing passes in'the' mill are operated at maximum capacity. 1

Certain features of the above-described apparatus are It is to be understood that the above-described ar-.

rangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall Within the spirit and scope thereof.

What is claimedis z.

1. In aconveyor system for a mill including a dispatch conveyor for delivering a billet to the mill, means for driving the dispatch conveyor, a billet detector positioned at a predetermined point along the dispatch conveyor for stopping the dispatch conveyor, a second billet detector positioned in' the milland actuating means operable by the second billetde'tector for starting=the} driving means to startv the dispatch conveyor. to deliv'er-a' billet thereonto the'rnill, therimprovement comprising-a timer, a pair or photoelectric relay means located between the detectors and spaced'apart' a predetermined distance for detecting anybillet longer than a predetermined length, means responsive to simultaneous actuation of the photoelectric relay means for actuating the timer, and a circuit operable by the timer for delaying action of the actuating means by the second billet detector.

2. In a mill including a first conveyor section, a second conveyor section, a rolling mill positioned beyond the second conveyor section, means for driving the first conveyor section to deliver a billet to the second conveyor section, means for driving the second conveyor section continuously to convey the billet away from the first conveyor section to the rolling mill, means operable by a billet on the first conveyor section forstoppirig abillet at a pre-determined point'on'the first" conveyor section, and means operable by a billet'at a predetermined point in the rolling mill for actuating the firstconveyor section driving means to start the first conveyor section to deliver a billet from the predetermined point on-said first conveyor section to the second conveyor. section, the. im-' provement comprising means for detecting any. billet longer than a predetermined lengthinthe mill prior to the arrival thereof atsaid point therein, and means for delaying the operation of the actuating means after actuation thereof by' abillet in accordance with the length of the last-mentioned billet. L Q;

3. A rolling 'mill conveyor system, which comprises a series of roughing rolls, a'first'serisoffinishing rolls, a second series of finishing rolls, means for feeding a first billetfrom the roughing rolls to the first series of finishing rolls and a second billet to the second series of finishing rolls, means for dispatching billets one at a time to the roughing rolls, means for. detecting each billet longer than a predeterminedflength 'as it. goes through the roughing mill, actiiatingimeans located beyond the detecting means andirespons'ive'to. each billet for actuating the dispatchingimeanse'to 'dispatch.the: next billet, 'a first timer means; as'econd tiinei inean's, means responsive to thedetectingimeansifor actuating the first timer means whenever the first billet of a predetermined length is detected, means responsive to the detecting means for actuating the second timer means whenever the second billet of said predetermined length is detected, means for operatively connecting the first timer means and the actuating means to-delay the dispatching means When the second billet actuatesthe actuatingimeans; and-means for operatively connecting :thesecond': timer m'eansl and the actuating'rneans to" delay the dispatchingm'eans when the first billet actuates the actuating means.

4. A rolling mill, which comprises a series of roughing rolls, a first series offinishing rolls, a second series of finishing rolls, means for feeding a first billet of a series 9 from the roughing rolls to the first series of finishing rolls and a second billet to the second series of finishing rolls, means for dispatching billets one at a time to the roughing rolls, means for detecting each billet as it goes through the roughing mill, actuating means located beyond the detecting means and responsive to each billet for actuating the dispatching means to dispatch the next billet, a first timer means, a second timer means, means responsive to the detecting means for starting the first timer means the first billet of a predetermined length is detected, means responsive to the detecting means for starting the second timer means when the second billet of said predetermined length is detected, circuit means for operatively connecting the first timer means and the actuating means to delay the dispatching means When the second billet actuates the actuating means and the first timer means has been actuated and disconnecting the first timer means and the actuating means while the first billet operates the actuating means, and circuit means for operatively connecting the second timer means and the actuating mean to delay the dispatching means when the first billet actuates the actuating means and the second timer means has been actuated and disconnecting the second timer means and the actuating means while the second billet actuates the actuating means.

5. A rolling mill, which comprises a series of roughing rolls, a first series of finishing rolls, a second series of finishing rolls, means for feeding a first billet of a series from the roughing rolls to the first series of finishing rolls and a second billet to the second series of finishing rolls, means for dispatching billets one at a time to the roughing rolls, detecting means responsive to a billet at least of a predetermined length as it goes through the roughing mill, actuating means located beyond the detecting means and responsive to each billet for actuating the dispatching means to dispatch the next billet, a first timer means, a second timer means, means responsive to the detecting means for starting the first timer means when the first billet of at least said predetermined length is detected, means responsive to the detecting means for starting the second timer means when the second billet of at least said predetermined length is detected, means for operatively connecting the first timer means and the actuating means to delay the dispatching means when the second billet actuates the actuating means and the first timer means has been started and disconnecting the first timer means and the actuating means while the first billet actuates the actuating means, and means for operatively connecting the second timer means and the actuating means to delay the dispatching means when the first billet actuates the actuating means and the second timer means has been started and disconnecting the second timer means and the actuating means While the second billet actuates the actuating means.

6. In a rolling mill including a first series of rolls, means for guiding a billet automatically through the series of rolls, a second series of rolls, a third series of rolls, means for dispatching billets one at a time to the first series of rolls, and means for guiding automatically a first billet in order of dispatch to the second series of rolls and a second billet in order of dispatch to the third series of rolls, the improvement comprising means for detecting the length of each billet as it is moved through the first series of rolls, actuating means positioned adjacent to the path of the billets at a point beyond the detecting means and operable by each billet for actuating the dispatching means, a first timer means operable by the actuating means for preventing operation of the dispatching means for a predetermined period of time after actuation by the actuating means, a second timer means, a third timer means, relay means responsive to the detecting means for setting up the second timer means for starting by the first billet longer than a predetermined length, a second relay means responsive to the detecting means for setting up the third timer 10 means for starting by the second billet longer than said predetermined length, and memory circuit means for starting the first timer mea as the second timer means times out and the actuating means is actuated by the second billet and starting the first timer means as the third timer means times out and the actuating means is actuated by the first billet.

7. In a rolling mill including a first series of rolls, means for guiding a billet automatically through the series of rolls, a second seriesi of rolls, a third series of rolls, means for dispatching billets one at a time to the first series of rolls, and means for guiding automatically a first billet in order of dispatch to the second series of rolls and a second billet in order of dispatch to the third series of rolls, the improvement comprising a pair of photoelectric means positioned a predetermined distance apart along the path of the billets in the first series 012 rolls for detecting the length of each billet as it is moved through the first series of rolls, photoelectric actuating means positioned adjacent to the path of the billets at a point beyond the photoelectric detecting means and operable by each billet for actuating the dispatching means, a first timer means operable by the photoelectric actuating means for preventing operation of the dispatching means for a predetermined period of time after actuation by the actuating means, a second timer means, a third timer means, relay means responsive to simultaneous actuation of the pair of photoelectric detecting means for setting up the second timer means for starting by the first billet longer than said predetermined distance, a second relay means responsive to simultaneous actuation of the pair of photoelectric detecting means for seting up the third timer means for starting by the second billet longer than said predetermined distance, circuit means for starting the first timer means as the second timer means times out and the photoelectric actuating means is actuated by the second billet and starting the first timer means as the third timer means times out and the photoelectric actuating means is actuated by the first billet.

8. In a rolling mill having a first series of rolls, means for guiding a billet through the first series of rolls, a second series of rolls, means for dispatching billets one at a time to the first series of rolls, and means for guiding the billets from the first series of rolls to the second series of rolls, a system for controlling the dipatching means comprising first photoelectric means positioned adjacent to the path of the billet leaving the first series of rolls, second photoelectric means positioned adjacent to said path and spaced from said first photoelectric means a predetermined distance, third photoelectric means positioned adjacent to said path and spaced from the first photoelectric means a distance greater than said predetermined distance, a timer for actuating the dispatching means, fourth photoelectric means positioned adjacent to the path of the billet leaving the second series of rolls for actauting the timer to operate the dispatching means, first timing means responsive to simultaneous actuation of the first and second photoelectric means by a billet for delaying actuation of the timer for a predetermined period, and second timing means responsive to simultaneous actuation of said first and third photoelectric means for delaying actuation of the timer for a period greater than said predetermined period.

References Cited in the file of this patent UNITED STATES PATENTS 1,469,575 Baehr Oct. 2, 1923 1,736,076 George Nov. 19, 1929 1,883,140 Walter Oct. '18, 1932 1,951,426 Littler Mar. 20, 1934 2,171,362 Gulliksen Aug. 29, 1939 2,290,443 Morrison July 21, 1942 2,737,834 Cuughlin et a1. Mar. 13, 1956 

